power: supply: sc27xx: Fix external_power_changed race

sc27xx_fgu_external_power_changed() dereferences data->battery,
which gets sets in ab8500_btemp_probe() like this:

data->battery = devm_power_supply_register(dev, &sc27xx_fgu_desc,
&fgu_cfg);

As soon as devm_power_supply_register() has called device_add()
the external_power_changed callback can get called. So there is a window
where sc27xx_fgu_external_power_changed() may get called while
data->battery has not been set yet leading to a NULL pointer dereference.

Fixing this is easy. The external_power_changed callback gets passed
the power_supply which will eventually get stored in data->battery,
so sc27xx_fgu_external_power_changed() can simply directly use
the passed in psy argument which is always valid.

After this change sc27xx_fgu_external_power_changed() is reduced to just
"power_supply_changed(psy);" and it has the same prototype. While at it
simply replace it with making the external_power_changed callback
directly point to power_supply_changed.

Cc: Orson Zhai <orsonzhai@gmail.com>
Cc: Chunyan Zhang <zhang.lyra@gmail.com>
Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Reviewed-by: Baolin Wang <baolin.wang@linux.alibaba.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply_core: Pass pointer to battery info

The function to retrieve battery info (from the device tree) assumes
we have a static info struct that gets populated by calling into
power_supply_get_battery_info().

This is awkward since I want to support tables of static battery
info by just assigning a pointer to all info based on e.g. a
compatible value in the device tree.

We also have a mixture of static and dynamically allocated
variables here.

Bite the bullet and let power_supply_get_battery_info() allocate
also the memory used for the very top level
struct power_supply_battery_info container. Pass pointers
around and lifecycle this with the psy device just like the
stuff we allocate inside it.

Change all current users over.

As part of the change, initializers need to be added to some
previously uninitialized fields in struct
power_supply_battery_info.

Reviewed-By: Matti Vaittinen <matti.vaittinen@fi.rohmeurope.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: sc27xx: Delete superfluous error message

In the function sc27xx_fgu_probe(), when get irq failed,
platform_get_irq() logs an error message, so remove
redundant message here.

Signed-off-by: Tang Bin <tangbin@cmss.chinamobile.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: sc27xx: Add missing MODULE_DEVICE_TABLE

This patch adds missing MODULE_DEVICE_TABLE definition which generates
correct modalias for automatic loading of this driver when it is built
as an external module.

Reported-by: Hulk Robot <hulkci@huawei.com>
Signed-off-by: Zou Wei <zou_wei@huawei.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: sc27xx: prevent adc * 1000 from overflow

The input parameter is int type, cause adc * 1000 could overflow.
Change to use s64 to avoid this issue.

Signed-off-by: Chen Yongzhi <yongzhi.chen@unisoc.com>
Signed-off-by: Chunyan Zhang <chunyan.zhang@unisoc.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: sc27xx: Add boot voltage support

Add new property to allow to get the voltage measured during boot time.

Signed-off-by: Yuanjiang Yu <yuanjiang.yu@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang7@gmail.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: sc27xx: Add CURRENT_NOW/VOLTAGE_NOW properties support

Add new properties to get present current and voltage of the fuel gauge.

Signed-off-by: Yuanjiang Yu <yuanjiang.yu@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang7@gmail.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: sc27xx: Allow to change the battery full capacity

The battery full capacity can be affected by the temperature or the
servicing time or other factors, so some platforms will track the
real battery full capacity in charger manager service. Thus we should
allow to change the battery full capacity by setting the
'POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN' property as writeable.

Signed-off-by: Yuanjiang Yu <yuanjiang.yu@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang7@gmail.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: sc27xx: Set 'no_thermal' flag for SC27xx fuel gauge

There is no thermal zone should be created for the SC27XX FGU power supply,
thus set the 'no_thermal' flag as true.

Signed-off-by: Yuanjiang Yu <yuanjiang.yu@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang7@gmail.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: sc27xx: Add POWER_SUPPLY_PROP_CHARGE_NOW attribute

Add the POWER_SUPPLY_PROP_CHARGE_NOW attribute to allow user to get
current battery capacity (uAh) to do measurement.

Signed-off-by: Baolin Wang <baolin.wang7@gmail.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: sc27xx: Calibrate the resistance of coulomb counter

There are some deviations between the real resistance and the ideal
resistance of coulomb counter, which will affect the accuracy of
the coulomb counter, thus calibrate the real resistance of coulomb
counter to improve the accuracy.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Baolin Wang <baolin.wang7@gmail.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: sc27xx: Optimize the battery resistance with measuring temperature

Optimize the battery internal resistance in a certain temerature to
get a accurate battery internal resistance.

Signed-off-by: Yuanjiang Yu <yuanjiang.yu@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Baolin Wang <baolin.wang7@gmail.com>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: sc27xx: Add POWER_SUPPLY_PROP_CALIBRATE attribute

Add the 'POWER_SUPPLY_PROP_CALIBRATE' attribute to allow chareger manager
to calibrate the battery capacity.

Signed-off-by: Yuanjiang Yu <yuanjiang.yu@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: sc27xx: Optimize the battery capacity calibration

This patch factors out the capacity calibration into one single function
to calibrate the battery capacity, and adding more abnormal cases to
calibrate the capacity when the OCV value is not matchable with current
capacity.

Moreover we also allow to calibrate the capacity when charger magager
tries to get current capacity to make sure we give a correct capacity
for userspace.

Signed-off-by: Yuanjiang Yu <yuanjiang.yu@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: sc27xx: Make sure the alarm capacity is larger than 0

We must make sure the alarm capacity is larger than 0, to help to
calibrate the low battery capacity.

Signed-off-by: Yuanjiang Yu <yuanjiang.yu@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: sc27xx: Fix the the accuracy issue of coulomb calculation

The Spreadtrum fuel gauge will multiply by 2 for counting the coulomb
counter to improve the accuracy, which means the value saved in fuel
gauge is: coulomb counter * 2 * 1000ma_adc. Thus fix the conversion
formular to improve the accuracy of calculating the battery capacity.

Signed-off-by: Yuanjiang Yu <yuanjiang.yu@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: sc27xx: Fix conditon to enable the FGU interrupt

We should allow to enable FGU interrupt to adjust the battery capacity,
when charging status is POWER_SUPPLY_STATUS_DISCHARGING.

Signed-off-by: Yuanjiang Yu <yuanjiang.yu@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: sc27xx: Add POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN attribute

Add POWER_SUPPLY_PROP_ENERGY_FULL_DESIGN attribute to provide the battery's
design capacity for charger manager to calculate the charging counter.

Signed-off-by: Yuanjiang Yu <yuanjiang.yu@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: sc27xx: Replace devm_add_action() followed by failure action with devm_add_action_or_reset()

devm_add_action_or_reset() is introduced as a helper function which
internally calls devm_add_action(). If devm_add_action() fails
then it will execute the action mentioned and return the error code.
This reduce source code size (avoid writing the action twice)
and reduce the likelyhood of bugs.

Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
Reviewed-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: sc27xx: Introduce local variable 'struct device *dev'

Introduce local variable 'struct device *dev' and use it instead of
dereferencing it repeatly.

Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
Reviewed-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: sc27xx: Fix capacity saving function

We found sometimes we can not get the saving capacity to initialize the
battery capacity, the reason is the user area registers are put on power
always-on region, so we need delay some time to wait until values are
updated successfully.

Moreover we also should clear the USER_AREA_CLEAR register after setting
the USER_AREA_SET register, otherwise we can not save the values in the
USER_AREA_SET register.

Signed-off-by: Yuanjiang Yu <yuanjiang.yu@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: sc27xx: Fix the incorrect formula when converting capacity to coulomb counter

We should multiply the calibrated current data (cur_1000ma_adc) when
converting current capacity (mAh) to coulomb counter, which can get
an accurate coulomb counter from the fuel gauge controller.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: sc27xx: Add one property to read charge voltage

Add POWER_SUPPLY_PROP_CONSTANT_CHARGE_VOLTAGE property to get charge
voltage sampling by ADC controller, which is used to validate if the
charge voltage is in normal range or not in charger manager.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: sc27xx: Save last battery capacity

Our charger manager can optimize the battery capacity periodically, so
we can save last battery capacity into registers. Then next system
power-on, we can read the last saved battery capacity as the initial
battery capacity, which can make the battery capacity more accurate.

Signed-off-by: Yuanjiang Yu <yuanjiang.yu@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: sc27xx: Add suspend/resume interfaces

Add fuel gauge platform suspend and resume interfaces. In suspend state,
we should enable the low voltage and coulomb counter threshold interrupts
to wake up system to calibrate the battery capacity in lower voltage stage.

Signed-off-by: Yuanjiang Yu <yuanjiang.yu@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: sc27xx: Add fuel gauge low voltage alarm

Add low voltage alarm support to make sure the battery capacity
more accurate in lower voltage stage.

Signed-off-by: Yuanjiang Yu <yuanjiang.yu@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: sc27xx: Add fuel gauge calibration

This patch adds support to read calibration values from the eFuse controller
to calibrate the ADC values corresponding to current and voltage, which can
make the current and voltage data more accurate.

Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>

power: supply: Add Spreadtrum SC27XX fuel gauge unit driver

This patch adds the Spreadtrum SC27XX serial PMICs fuel gauge support,
which is used to calculate the battery capacity.

Original-by: Yuanjiang Yu <yuanjiang.yu@unisoc.com>
Signed-off-by: Baolin Wang <baolin.wang@linaro.org>
Acked-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Sebastian Reichel <sebastian.reichel@collabora.com>